The present invention relates to wireless digital networks, and in particular, to power saving in wireless access points.
Wireless digital networks are becoming ubiquitous in enterprises, providing secure and cost-effective access to resources. Those networks usually have one or more controllers, each controller supporting a plurality of access points (AP) deployed through the enterprise. WiFi networks operating in accordance with IEEE 802.11 standards are examples of such networks.
Access points operating in accordance with IEEE 802.11 standards support clients operating in different modes; these modes use different bandwidths, modulation techniques, and numbers of radio streams, ranging from a single radio transmitter/receiver designed to handle only 11 Mbit/sec 802.11b, to 3×3 802.11n systems using three transmit and receive streams to transfer data at speeds up to 300 Mbit/sec. The amount of power consumed by the radio portion of an access point designed for legacy (802.11a/b/g use) is substantially less than that used by a High Throughput (HT) 802.11n radio subsystem.
Legacy radios, those for 802.11a/b/g use only one radio transmitter/receiver. HT 802.11n radios use multiple radio transmitter/receiver/antenna subsystems, 2, 3, or even 4 transmit/receive subsystems per frequency band.
What is needed is a way of automatically reducing power in modern, 802.11n APs when operating in Legacy modes.